1. Field
Embodiments of the present invention relate generally to systems and methods with reservoirs and, in specific embodiments, to a system with a reservoir and a plunger that are shaped to limit a presence of gas in a fluidic medium expelled from the reservoir.
2. Related Art
According to modern medical techniques, certain chronic diseases may be treated by delivering a medication or other substance to the body of a patient. For example, diabetes is a chronic disease that is commonly treated by delivering defined amounts of insulin to a patient at appropriate times. Traditionally, manually operated syringes and insulin pens have been employed for delivering insulin to a patient. More recently, modern systems have been designed to include programmable pumps for delivering controlled amounts of medication to a patient.
Pump type delivery devices have been configured in external devices, which connect to a patient, and have been configured in implantable devices, which are implanted inside of the body of a patient. External pump type delivery devices include devices designed for use in a stationary location, such as a hospital, a clinic, or the like, and further include devices configured for ambulatory or portable use, such as devices designed to be carried by a patient, or the like. External pump-type delivery devices may contain reservoirs of fluidic media, such as, but is not limited to, insulin.
External pump-type delivery devices may be connected in fluid flow communication to a patient or user-patient, for example, through suitable hollow tubing. The hollow tubing may be connected to a hollow needle that is designed to pierce the skin of the patient and to deliver fluidic media there through. Alternatively, the hollow tubing may be connected directly to the patient as through a cannula, or the like.
Examples of some external pump type delivery devices are described in U.S. patent application Ser. No. 11/211,095, filed Aug. 23, 2005, titled “Infusion Device And Method With Disposable Portion” and Published PCT Application WO 01/70307 (PCT/US01/09139) titled “Exchangeable Electronic Cards For Infusion Devices” (each of which is owned by the assignee of the present invention), Published PCT Application WO 04/030716 (PCT/US2003/028769) titled “Components And Methods For Patient Infusion Device,” Published PCT Application WO 04/030717 (PCT/US2003/029019) titled “Dispenser Components And Methods For Infusion Device,” U.S. Patent Application Publication No. 2005/0065760 titled “Method For Advising Patients Concerning Doses Of Insulin,” and U.S. Pat. No. 6,589,229 titled “Wearable Self-Contained Drug Infusion Device,” each of which is incorporated herein by reference in its entirety.
External pump-type delivery devices may be connected in fluid-flow communication to a patient-user, for example, through suitable hollow tubing. The hollow tubing may be connected to a hollow needle that is designed to pierce the patient-user's skin and deliver an infusion medium to the patient-user. Alternatively, the hollow tubing may be connected directly to the patient-user as or through a cannula or set of micro-needles.
In contexts in which the hollow tubing is connected to the patient-user through a hollow needle that pierces skin of the user-patient, a manual insertion of the needle into the patient-user can be somewhat traumatic to the user-patient. Accordingly, insertion mechanisms have been made to assist the insertion of a needle into the user-patient, whereby a needle is forced by a spring to move quickly from a retracted position into an extended position. As the needle is moved into the extended position, the needle is quickly forced through the skin of the user-patient in a single, relatively abrupt motion that can be less traumatic to certain user-patients as compared to a slower, manual insertion of a needle. While a quick thrust of the needle into the skin of the user-patient may be less traumatic to some user-patients than a manual insertion, it is believed that, in some contexts, some user-patients may feel less trauma if the needle is moved a very slow, steady pace.
Examples of insertion mechanisms that may be used with and may be built into a delivery device are described in: U.S. patent application Ser. No. 11/645,435, filed Dec. 26, 2006, titled “Infusion Medium Delivery system, Device And Method With Needle Inserter And Needle Inserter Device And Method,”; and U.S. patent application Ser. No. 11/211,095, filed Aug. 23, 2005, titled “Infusion Device And Method With Disposable Portion” (each of which is assigned to the assignee of the present invention), each of which is incorporated herein by reference in its entirety. Other examples of insertion tools are described in U.S. Patent Application Publication No. 2002/0022855, titled “Insertion Device For An Insertion Set And Method Of Using The Same” (assigned to the assignee of the present invention), which is incorporated herein by reference in its entirety. Other examples of needle/cannula insertion tools that may be used (or modified for use) to insert a needle and/or cannula, are described in, for example U.S. patent application Ser. No. 10/389,132 filed Mar. 14, 2003, and entitled “Auto Insertion Device For Silhouette Or Similar Products,” and/or U.S. patent application Ser. No. 10/314,653 filed Dec. 9, 2002, and entitled “Insertion Device For Insertion Set and Method of Using the Same,” both of which are incorporated herein by reference in their entirety. Further examples of various insertion tools are described in, but are not limited to, U.S. patent application Ser. No. 11/645,972, filed Dec. 26, 2006, “Infusion Medium Delivery System, Device And Method With Needle Inserter And Needle Inserter Device And Method”; U.S. patent application Ser. No. 11/646,052, filed Dec. 26, 2006, “Infusion Medium Delivery System, Device And Method With Needle Inserter And Needle Inserter Device And Method”; U.S. patent application Ser. No. 11/646,000, filed Dec. 26, 2006, “Infusion Medium Delivery System, Device And Method With Needle Inserter And Needle Inserter Device And Method,” all of which are herein incorporated by reference in their entirety.
Pump-type delivery devices can allow accurate doses of insulin to be calculated and delivered automatically to a patient-user at any time during the day or night. Furthermore, when used in conjunction with glucose sensors or monitors, insulin pumps may be automatically controlled to provide appropriate doses of infusion medium at appropriate times of need, based on sensed or monitored levels of blood glucose.
Pump-type delivery devices have become an important aspect of modern medical treatments of various types of medical conditions, such as diabetes. As pump technologies improve and as doctors and patient-users become more familiar with such devices, the popularity of external medical infusion pump treatment increases and is expected to increase substantially over the next decade.